'\" te
.\" Copyright (c) 2000, Sun Microsystems, Inc. All Rights Reserved.
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
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.TH PTREE_REGISTER_HANDLER 3PICLTREE "Aug 1, 2000"
.SH NAME
ptree_register_handler \- register a handler for the event
.SH SYNOPSIS
.LP
.nf
\fBcc\fR [ \fIflag\fR... ] \fIfile\fR... \fB-lpicltree\fR [ \fIlibrary\fR... ]
#include <picltree.h>

\fBint\fR \fBptree_register_handler\fR(\fBconst char *\fR\fIename\fR,
     \fBvoid (*\fR\fIevt_handler\fR)(\fBconst char *\fR\fIename\fR, const void *\fIearg\fR,
     \fBsize_t\fR \fIsize\fR, \fBvoid *\fR\fIcookie\fR), \fBvoid *\fR\fIcookie\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBptree_register_handler()\fR function registers an event handler for a
PICL event. The argument \fIename\fR specifies the name of the PICL event for
which to register the handler. The argument \fIevt_handler\fR specifies the
event handler function. The argument \fIcookie\fR is a pointer to
caller-specific data to be passed as an argument to the event handler when it
is invoked.
.sp
.LP
The event handler function must be defined as
.sp
.in +2
.nf
void evt_handler(const char *\fIename\fR, const void *\fIearg\fR, \e
        size_t \fIsize\fR, void *\fIcookie\fR)
.fi
.in -2

.sp
.LP
where, \fIename\fR, \fIearg\fR, \fIsize\fR, and \fIcookie\fR are the arguments
passed to the event handler when it is invoked. The argument \fIename\fR is the
PICL event name for which the handler is invoked. The arguments \fIearg\fR and
\fIsize\fR gives the pointer to the event argument buffer and its size,
respectively. The argument \fIcookie\fR is the pointer to the caller specific
data registered with the handler. The arguments \fIename\fR and \fIearg\fR
point to buffers that are transient and shall not be modified by the event
handler or reused after the event handler finishes execution.
.sp
.LP
The PICL framework invokes the event handlers in the order in which they were
registered when dispatching an event. If the event handler execution order is
required to be the same as the plug-in dependency order, then a plug-in should
register its handlers from its init function. The handlers that do not have any
ordering dependencies on other plug-in handlers can be registered at any time.
.sp
.LP
The registered handler may be called at any time after this function is called.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, \fB0\fR is returned. On failure, a non-negative
integer is returned to indicate an error and the handler is not registered.
.SH ERRORS
.sp
.ne 2
.na
\fB\fBPICL_INVALIDARG\fR\fR
.ad
.RS 19n
Invalid argument
.RE

.sp
.ne 2
.na
\fB\fBPICL_FAILURE\fR\fR
.ad
.RS 19n
General system failure
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Evolving
_
MT-Level	MT-Safe
.TE

.SH SEE ALSO
.sp
.LP
.BR ptree_unregister_handler (3PICLTREE),
.BR attributes (7)
